2 files changed, 49 insertions, 3 deletions

diff --git a/src/mailman/commands/eml_membership.py b/src/mailman/commands/eml_membership.py
index 4f46cfac7..88f7d5722 100644
--- a/src/mailman/commands/eml_membership.py
+++ b/src/mailman/commands/eml_membership.py
@@ -34,8 +34,9 @@ from zope.interface import implements
 
 from mailman.core.i18n import _
 from mailman.interfaces.command import ContinueProcessing, IEmailCommand
-from mailman.interfaces.member import DeliveryMode
+from mailman.interfaces.member import DeliveryMode, MemberRole
 from mailman.interfaces.registrar import IRegistrar
+from mailman.interfaces.subscriptions import ISubscriptionService
 from mailman.interfaces.usermanager import IUserManager
 
 
@@ -81,9 +82,14 @@ example:
             return ContinueProcessing.yes
         joins.add(address)
         results.joins = joins
-        getUtility(IRegistrar).register(mlist, address, real_name)
+        members = getUtility(ISubscriptionService).find_members(address)
         person = formataddr((real_name, address))
-        print >> results, _('Confirmation email sent to $person')
+        if len(members) > 0 and members[0].role is MemberRole.member:
+            assert(members[0].address.email == address)
+            print >> results, _('$person is already a member')
+        else:
+            getUtility(IRegistrar).register(mlist, address, real_name)
+            print >> results, _('Confirmation email sent to $person')
         return ContinueProcessing.yes
 
     def _parse_arguments(self, arguments):
diff --git a/src/mailman/runners/tests/test_join.py b/src/mailman/runners/tests/test_join.py
index 69ed682e2..369880a32 100644
--- a/src/mailman/runners/tests/test_join.py
+++ b/src/mailman/runners/tests/test_join.py
@@ -27,9 +27,11 @@ __all__ = [
 import unittest
 
 from email.iterators import body_line_iterator
+from zope.component import getUtility
 
 from mailman.app.lifecycle import create_list
 from mailman.config import config
+from mailman.interfaces.usermanager import IUserManager
 from mailman.runners.command import CommandRunner
 from mailman.testing.helpers import (
     get_queue_messages,
@@ -91,3 +93,41 @@ subscribe
         self.assertEqual(len(confirmation_lines), 1)
         # And the confirmation line should name Anne's email address.
         self.assertTrue('anne@example.org' in confirmation_lines[0])
+
+    def test_join_when_already_a_member(self):
+        anne = getUtility(IUserManager).create_user('anne@example.org')
+        self._mlist.subscribe(list(anne.addresses)[0])
+        # When someone tries to join by email and they are already a member,
+        # ignore the request.
+        msg = mfs("""\
+From: anne@example.org
+To: test-join@example.com
+Subject: join
+
+""")
+        self._commandq.enqueue(msg, dict(listname='test@example.com'))
+        self._runner.run()
+        # There will be one message in the queue - a reply to Anne notifying
+        # her of the status of her command email.  Because Anne is already
+        # subscribed to the list, she gets and needs no confirmation.
+        messages = get_queue_messages('virgin')
+        self.assertEqual(len(messages), 1)
+        self.assertEqual(messages[0].msg['subject'],
+                         'The results of your email commands')
+        # Search the contents of the results message.  There should be just
+        # one 'Confirmation email' line.
+        confirmation_lines = []
+        in_results = False
+        for line in body_line_iterator(messages[0].msg, decode=True):
+            line = line.strip()
+            if in_results:
+                if line.startswith('- Done'):
+                    break
+                if len(line) > 0:
+                    confirmation_lines.append(line)
+            if line.strip() == '- Results:':
+                in_results = True
+        # There should be exactly one confirmation line.
+        self.assertEqual(len(confirmation_lines), 1)
+        # And the confirmation line should name Anne's email address.
+        self.assertTrue('anne@example.org' in confirmation_lines[0])